We plan to investigate parameters that will affect the differentiated structure and function of the primary epithelial cell cultures from both the dog and rat. These include: supplementation of the culture medium with hormones (including sex hormones) and growth factors; growing the cells on various substrates including prostate derived fibroblasts, fibronectin, and collagen matrices. The effects of these perturbations on androgen metabolism, acid phosphatase production, ornithine decarboxylase production, steroid binding capacity and formation of secretory granules and intercellular junctions will be monitored.